The objective of the proposed research is to elucidate the neural control of three physiological areas: the coronary circulation, the cerebral circulation, and renin secretion. A research plan is presented for first demonstrating the autonomic control of the coronary and cerebral circulations by direct nerve stimulation followed by experiments on reflex control of these vascular beds. Autonomic control of myocardial oxygen tension will be studied and a chronic preparation for measuring cerebral blood flow in dogs is proposed. Our previous research has demonstrated hypothalamic control of renin secretion - via renal sympathetic nerves. This work will be extended to determine if renin secretion is modulated by psychological stress, and if so by what pathway.